C. diff Flashcards
C. difficile Microbiology Basics
Gram ___ , ___ forming, obligate ___ bacillus
Transmitted person-to-person via fecal-oral route through ingestion of spores
- +, spore, anaerobic
C. difficile Infection Risk Factors
1) Antibiotic exposure
2) Healthcare exposure
3) Age ≥ __ years
4) Proximity to person with C. difficile infection
5) Use of acid suppressing agents ( ___ and ___ )
6) Chemotherapy
7) Immunosuppression
8) GI surgery
- 65
- PPI, H2RA
C. difficile Infection Risk Factors – Antibiotic Exposure
Highest Risk Antibiotics (4)
1) Fluoroquinolones
2) Clindamycin
3) 3rd/4th Generation Cephalosporins
4) Carbapenems
Signs and Symptoms of C. difficile Infection
Two primary symptoms:
- ___ , ___ , or mucoid ___ , foul-smelling diarrhea
- Abdominal pain
Additional signs and symptoms:
- Fever
- Leukocytosis
- Hypoalbuminemia
- Acute kidney injury
- profuse, watery, green
C. difficile Infection Laboratory Testing and Diagnosis
test when ≥ __ profuse, watery, green, foul smelling stools in 24 hrs
Three testing methods utilized for most sensitive results
1. Nucleic acid amplification test (NAAT) alone (in conjunction with signs/symptoms)
2. Antigen test (GDH) + Toxin A/B test (NAAT used to resolve discordant results)
3. NAAT + Toxin A/B test
Repeat testing within __ days of same episode of diarrhea has limited value and is not recommended
- Not recommended to test asymptomatic patients or samples with formed stool
- 3
- 7
C. difficile Infection Severity
Non-Severe
- WBC ≤ ___ /mcL
- SCr < ___ mg/dL
Severe
- WBC > ___ /mcL
- SCr > ___ mg/dL
Fulminant
- ___ or shock
- ___
- Toxic ___
- 15,000, 1.5
- hypotension
- ileus
- megacolon
C. difficile Infection Treatment Options – Types of “Weed Killers”
Oral Vanc
- broad spectrum
- standard of care
Fidaxomicin
- ___ spectrum
- higher rates of sustained response
Metronidazole (IV or PO)
- No longer recommended as first-line
- Reserved for ___ cases as additional agent
- narrower
- fulminant
Oral Vancomycin – Key Information/Considerations
Recommended dosing strategies
- Standard dosing – vancomycin ___ mg PO Q6H
- Fulminant CDI dosing – vancomycin ___ mg PO Q6H
- 125
- 500
Fidaxomicin (Dificid ®) – Key Information/Considerations
Pharmacokinetic/pharmacodynamic considerations
- ___ synthesis inhibitor
- Extremely poor oral absorption
Standard dosing – fidaxomicin 200 mg PO Q12H
___ rates of sustained treatment response and lower ___ rates
- expensive tho
- protein
- higher, recurrence
Metronidazole – Key Information/Considerations
Pharmacokinetic/pharmacodynamic considerations
- Excellent oral absorption (> 90%)
Standard dosing – metronidazole 500 mg __ Q8H
Fulminant CDI dosing – metronidazole 500 mg __ Q8H
___ efficacious and ___ risk for recurrence
- cheap
- PO
- IV
- less, higher
T or F: we want to avoid peristatic agents like loperamide
TRUE
- want to get that nasty stuff out, keep the diarrhea going
C. difficile Infection Treatment Recommendations
in order of preference
- ___ 200 mg PO Q12H x 10 days
- ___ 125 mg PO Q6H x 10 days
- Fidaxomicin
- Vancomycin
only to metro if other options arent available
General treatment approach with recurrent CDI
Change something – either the drug or dosing regimen
C. difficile Infection Treatment Recommendations
Fulminant CDI
(in order of preference)
- ___ 500 mg PO Q6H +
___ 500 mg __ Q8H
If ileus present, consider adding vancomycin 500 mg via ___ instillation Q6H
Treatment duration not as well defined
- vancomycin
- metronidazole, IV
- rectal
Strategies to Reduce CDI Recurrence
Fecal Microbiota Transplant (FMT) = Rolling out new grass
___ (fecal microbiota susp, live-jslm) = Rolling out new grass
- requires ___ tube
- $$$
___ (fecal microbiota, live-brpk) = Planting new seeds
- Modulate bile acid concentrations and restore fatty acids, which results in resistance to C. difficile colonization and restoration of the gut microbiome
- ___ option!
- $$$
- Side effects – abdominal distention, fatigue, constipation, chills, diarrhea
___ (Zinplava ®) = Reduce weed damage
- Monoclonal antibody targeting C. difficile ___ to neutralize its effect
- Caution in patients with ___ (↑ risk of CHF and mortality?)
- $$$
- Rebyota, rectal
- Vowst, oral
- Bezlotoxumab, toxin B
- CHF
probiotics not great
- no data
- potential for bloodstream infections
- Abx kill them anyway (wimpy probiotic bacteria)
History of CDI – What should I do if I need antibiotics again?
Oral vancomycin ___ has been studied
- Common dose is vancomycin 125 mg PO Q12H during and for 3-5 days after completion of antibiotic therapy
- Current studies are limited by retrospective designs and small patient population
- Unclear what effect this can have on normal gut microbiome and future CDI recurrences
prophylaxis
